Small amounts of highly toxic dioxin are showing up in a range of paper products - from disposable diapers to paper towels. These levels of contamination do not pose an immediate risk to human health, according to the Environmental Protection Agency, which released its long-delayed national dioxin study yesterday.
Of particular concern: food-packaging products and personal-care items.
The disclosures of dioxin in paper products came Wednesday, after the environmental group Greenpeace released a packet of leaked documents showing that the industry has known about the problem since February, if not before. The link between paper mills and dioxin has been confirmed by a separate study by the industry and the EPA.
The dioxin, a controversial and toxic contaminant, is apparently formed in a chlorine bleaching process used in about 90 United States kraft paper mills, which produce most of white paper con sumers use.
Most scientists are not sure what threat, if any, the tainted paper poses, since they are not at all certain how dangerous dioxin is to humans beings.
``We just don't know,'' says Dr. Jake Ryan, a research scientist with Health and Welfare Canada, an agency similar to the US Food and Drug Administration. ``One of the big problems is that people have been looking for a long-term low-level effect in people. And to date, they haven't found one.''
Some studies have shown, however, that the substance - 2,3,7,8 tetrachlorodibenzo-p-dioxin, or TCDD - has caused cancer, birth defects, and damage to the immune system of animals. Because of the new evidence about paper, environmentalists are now calling for the EPA to restrict or eliminate TCDD and other dioxins in paper.
``We're talking about direct human contact,'' says Dr. Ellen Silbergeld, a toxicologist with the Environmental Defense Fund. ``It is irresponsible not to show concern.''
But the industry is urging more testing.
``The next step, from our standpoint, concerns a broad range of things,'' says Red Cavaney, president of the American Paper Institute, the industry group that is coordinating the dioxin studies. The industry plans to expand its program to test all bleach kraft paper mills, continue its risk assessment of the human hazard, and investigate exactly how the dioxin is formed in the bleaching process.
On Sept. 1, the Monitor first reported the link between paper mills and dioxin established in the joint study by the EPA and the industry. At the time, government researchers had found detectable amounts of TCDD in the discharges of mills in Jay, Maine, International Falls, Minn., and Wauna, Ore. Two other mills - in Chillicothe, Ohio, and Lufkin, Texas - did not show detectable discharges.
According to Greenpeace officials, it was the Monitor article that prompted an American Paper Institute employee to step forward and leak several internal documents. It was the documents that prompted further questions about TCDD in paper products.
The new information is that up to 50 parts per trillion of TCDD have been found in seven of the nine pulps tested in these mills. In further tests, sponsored by the industry, researchers have found TCDD and a related dioxin in paper products themselves. In superabsorbent disposable diapers, for example, tests showed up to 11 parts per trillion of dioxin; in paper towels, up to 7 parts per trillion; in a composite of various paper plates, up to 10 parts per trillion.
The counts could be somewhat higher if other scientists were doing the calculations. Nevertheless, the industry is quick to point out that these amounts are nowhere near the danger zone, according to the calculations of two laboratories it has contracted to do the risk assessment. For the disposable diapers, for example, it would take 39,000 parts per trillion of dioxin to increase the risk of cancer; in paper towels, 6.2 million parts per trillion.
Other dioxin experts are wary of any kind of risk-assessment numbers.
``It's numbers-slinging,'' says a Midwestern dioxin expert. The danger of dioxin is probably overblown and the EPA is probably being far too cautious in limiting exposures, he adds. ``I'm not alarmed. They've always had dioxin in paper. It's just that they haven't been able to detect it'' until now.
What is also clear, however, is that the industry was very sensitive about consumers finding out about dioxin in its paper products. Greenpeace officials charge that the EPA and the industry tried to cover up the information. Both EPA and the industry deny this charge. The internal documents leaked to Greenpeace paint a third picture, not exactly of a cover-up, but a more subtle, clever program to play down and manage the information that did get out.
For example, when the Monitor asked last month why the industry had embarked on a joint study with the EPA - an unusual procedure for the agency - industry spokeswoman Carol Raulston answered that the industry was just as eager as anyone to get to the bottom of the matter.
But according to a Dec. 30, 1986, internal industry memo, the real reason for the joint study was to ``forestall major regulatory and public relations difficulties.''
Other documents show the industry pressuring the EPA to play down the information. When the agency agreed last spring to grant a Freedom of Information Act request on the dioxin material, it agreed ``to characterize the information as meaningless,'' according to a March 18 letter by Ms. Raulston.
The industry, meanwhile, was busy training spokesmen, creating ``response teams,'' and holding strategy sessions to hit upon the best way to handle the release of the information. One staff member at the American Paper Institute wrote Raulston on Aug. 31: ``... The paper industry findings could engender press interest. As has been our goal all along, we need to prepare materials that would temper that interest. I suggest we do that by making the paper industry findings appear as `old news.'''
The industry had already conducted low-key briefing sessions with selected members of the press in the five states where the mills were being studied. ``The communications objectives of the visits ... were to ensure that any press accounts of the study were accurate and local, as opposed to national, in scope,'' one document explained.